
INSTRUCTIONS 
FRENCH LIGHTS 


TC 377 
. F74 

1845 
Copy 1 


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ON THE 

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ORGANIZATION AND SUPERINTENDENCE 



LIGHTHOUSES AND BEACONS, 


ON THE COASTS OP FRANCE. 


y 


'&rati5lat*ir ft :um tfj* £ttncl). 


WASHINGTON: 

C. ALEXANDER) PRINTER. 

1845. 














TABLE OF CONTENTS. 


PAGE. 

Introduction. 3 

SECTION I.—On the composition and use of the Apparatus for the Illumination 

of Maritime Lighthouses.*. 4 

Chapter 1. Lenticular Lighthouses and Beacons. 5 

Sec. 1 . Optic System. 5 

Sec. 2. Furniture of Lenticular Apparatus. 8 

Sec. 3. Mechanical and other Lamps used in illumina¬ 
ting Lighthouses and Lenticular Beacons.... 9 

Sec. 4. Rotary Machines. 20 

Chapter 2. Catoptric Lighthouses and Beacons.... 22 

Sec. 1 . Composition of the Reverberating Apparatus... 22 

Sec. 2. Lamps with Reverberating Apparatus. 23 

Sec. 3.. Rotary Machines. 24 

SECTION II.—Organization of the Service of Lighthouses. 24 

Chapter 1 . Materiel .*. 25 

Sec. 1 . Fitting up of Beacons and Lighthouses. 25 

Sec. 2. On the proper keeping of the Lanterns and 


Lighting Apparatus. 28 

V 

Sec. 3. Mountings, Utensils, and various objects. 32 

Sec. 4. Supplies of Oil, Wicks, Chimneys, Linen, &c.. 33 

Sec. 5. Keeping the buildings in order. 36 

Chapter 2 . Personnel. 37 

SECTION III.—Direction and Inspection of the Service of Lighthouses and 

Beacons. 41 

Chapter 1. Lenticular Lights of the three first orders. 41 

Sec. 1. Lighting Apparatus and Lanterns. 41 

* » 

Sec. 2. Supplies, Utensils, and Implements. 48 

Sec. 3. Lodging and Furniture. 49 

Sec. 4. General condition, Register of the Watch, [Log.] 50 

Chapter 2. Lenticular Beacons of the fourth order. 50 

Chapter 3. Reverberatory Lights and Beacons. 53 
























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1 




CODE OF INSTRUCTION 


ON THE 

ORGANIZATION AND SUPERINTENDENCE 


O F 


LIGHTHOUSES AND BEACONS. 


This code of general instruction on the management of the de¬ 
tails of maritime Lighthouses might have been much abridged, as 
to the special instructions concerning illumination, by more fre¬ 
quent references to works written on the subject, as well as to the 
regulations now in operation. But this course would have merely 
subjected the reader to embarrassing researches; for, with the ex¬ 
ception of the Code of Instruction (published in 1835) upon the 
management of lenticular Lighthouses of the three first Orders, 
all those documents are still in manuscript. 

It became, therefore, necessary to exhibit here a summary of 
the whole; and it has, moreover, been deemed useful to preface 
our work by some general views and theoretical sketches not to 
be found in those manuals published for the use of Lighthouse- 
Keepers. 

Those General Views form the subject of the First Section . 

The Second Section embraces the Organization of the Service. 

The Third and last Section , which is in some degree the corol¬ 
lary of the other two, corresponds in a special manner with the 





4 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


title of this work, by pointing out the course to be pursued, and 
by marking the essential points to be considered in the care and 
superintendence of the Lighthouse Service. 

FIRST SECTION. 

ON THE COMPOSITION AND USE OF THE APPARATUS FOR THE 
ILLUMINATION OF MARITIME LIGHTHOUSES. 

Two Classes of Lighting Apparatus. 

* * \ i 

The Lighthouses and Beacons on the Coast of France are divided, 
with regard to the mode of illuminating them, into two classes, 
essentially distinct: the first class comprising the new Establish¬ 
ments, lighted by lenticular or dioptric Apparatus; and the 
second, those lighthouses and beacons with reflectors or catop¬ 
tric Apparatus. 

In each system, the principal condition required is to direct 
towards the horizon the rays emanating from one or more foci of 
light. 

Four principal orders of Lenticular Apparatus. 

The Lenticular Apparatus have been hitherto classed into four 
principal orders. The three first orders comprise those Light¬ 
houses which embrace a horizon of from 15 to 30 nautical miles; 
and the fourth order includes those plain Beacons whose horizon 
reaches not much beyond 9 to 12 nautical miles. 

This classification has not been applied to Apparatus with rever¬ 
berating reflectors. Those are commonly divided into two Orders, 
according to their disposition, either for illuminating Lighthouses, 
properly so called, or for the use of mere Beacons at the entrance 
of harbors. 

In the Apparatus for illuminating Lighthouses, their species is 
to be particularly considered— 

1st. The Optic System , as well as the effects of light thence 
resulting. 

2d. The Apparatus which unites together the parts of the Op¬ 
tic System. 

3d. The species of Lamp employed for illuminating the Appa¬ 
ratus. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


5 


4th. Lastly, it the Light be changeable, the Rotary Machine 
which puts in play the moveable optic parts. 

CHAPTER I. 

LENTICULAR LIGHTHOUSES AND BEACONS. 

SECTION 1. 

OPTIC SYSTEM. 

The Optic System of Lenticular Apparatus is composed of two 
parts—the one principal, the other accessory. 

The principal part is a dioptric drum , the centre of whose 
figure corresponds to the common focus. 

The accessory part, intended to utilize the luminous rays which 
pass both above and below the dioptric drum, or which would 
diverge on the side of the land, is formed either of lenticular panes 
of glass combined with plain mirrors , or of simple belts of con¬ 
cave mirrors , or, finally, of refracting and reflecting rings , called 
catadioptric rings. 

Characters of the Lights. 

Three principal characters result, in regard to the lights, from 
the different combinations to which the construction of the diop¬ 
tric drums has been hitherto submitted, namely : 

1st. Fixed light. 

2d. Light with eclipses. 

3d. Light varied by flashes, preceded and followed by brief 
Eclipses. Colored Lights have been discarded from the general 
system of lighting the coasts of France, and have been admitted 
merely as exceptions, in some circumstances. 

Apparatus for Fixed Light.—Figure 1 .—Plate 1. 

The Drum of glass of an Apparatus for fixed light may be 
considered as produced by the revolution round its axis of a verti¬ 
cal segment placed so as to refract horizontally the rays emanating 
from the focus. (1.) 


(1.) The generating Segment might, theoretically, be described as a continued curve. 
But, on this hypothesis, the central zone would present a disproportioned thickness; 



6 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


Apparatus for Eclipses.—Figure 2 .—Plate 1. 

If we suppose that the generating segment, instead of turning 
round the vertical Axis passing through its focus, turns round the 
horizontal Axis, it will produce, in its new revolution, a disc with 
concentric Zones, having the property ot refracting perpendicu¬ 
larly to its plane all the rays which it shall receive from the focus. 
The light would then be transmitted in a cylindrical fascine or 
assemblage of rays, if the illuminating body was reduced to a 
mathematical point; but in proportion to the greater or smaller 
dimensions of the focal flame, the assemblage of rays represented 
will diverge more or less. 

Figure 3 .—Plate 1. 

If we suppose now that a prismatic drum formed of a collection 
of panes of this sort, illuminated by a common focus, were to re¬ 
ceive a rotary motion around its axis, there will appear on the 
horizon as many luminous groups of rays as there will be panes 
of glass, and the appearance of each flash will be preceded and 
followed by an Eclipse. The duration of this appearance will, 
moreover, be measured by the ratio between the divergence ot 
the rays and the velocity of rotation. 

Such is the arrangement of the principal part of the lenticular 
Lighthouses with Eclipses. 

Apparatus with Fixed Lights , varied hy flashes.—Figure 4.— 

Plate L 

„ The third combination consists in causing to revolve round a 
dioptric drum of the first sort, two or three lenticular panes of 
glass, formed of cylindrical vertical elements, whose horizontal 


and it is on this account that recourse has been had to the echelon-figure , in which the 
useless matter is dispensed with. It is, besides, to be observed, that the decomposition 
of the solid substance of glass into zones, which are executed separately, allows the 
aberration of sphericity to be attenuated; and by so much the more, as the divisions 
are more multiplied. 

The casting and cutting of the annular zones of dioptric drums with fixed light, 
present, for the apparatus of the three first orders, great difficulties. These difficulties 
were obviated at the commencement of the manufacture, by substituting for the circu¬ 
lar rings, a polygonal assemblage of prismatic elements; but now all those pieces are 
executed in the annular form. 



CODE OF INSTRUCTION ON LIGHTHOUSES. 


7 


section fulfils the condition of refracting, parallel to its axis, the' 
diverging rays emanating from the fixed drum. 

The interposition of these moveable panes produces thus a : 
lively flash, which is preceded and followed by a brief eclipse , 
after which reappears the fixed light. 

Accessory part of the Apparatus — Mirrors. — Figured.—Plate 2. 

The accessory part of the lenticular Apparatus, serving to illu¬ 
minate Lighthouses of extensive prospect, is generally formed of 
a fixed system of concave mirrors arranged in horizontal Zones 
above and below the dioptric Drum. 

Each of these Zones may be considered as generated by the 
revolution of a parabolic arc having for focus that of the appara¬ 
tus, and revolving round the vertical axis passing through the 
said focus. (1.) They are, besides, arranged echelon-wise , so as to 
collect all the rays contained in that part of the luminous sphere 
which they embrace. 

Those zones are composed of larger or smaller Mirrors, accord¬ 
ing to the order of the Apparatus. 

Each of those mirrors is supported by three claws screwed ; 
and its position is regulated when, by placing the eye at the focal 
point, the maritime horizon appears depicted on the middle of the 
glass. 

Accessory part of the Apparatus. 

At the two lighthouses of Cordovan and Marseilles, the diop¬ 
tric revolving drum is surmounted by an accessory system equally 
moveable, composed of eight lenticular panes, and as many plane 
Mirrors. 


(1.) This community of focus with the dioptric drum takes place only in the upper 
zones. The lower zones have each a specific focus a little higher at the first, and by 
so much more elevated as they are lower—an arrangement required by the opacity of 
the socket. 

The same remark applies to the catadioptric rings of the small apparatus of the 4th 
order. 

In the impossibility of imparting to the glasses a parabolic curvature, we have as¬ 
sumed, as generator of each zone, the arc of the oscillating circle at the middle point 
of the parabolic arc which it embraces. These glasses have also been moulded under 
a cylindric or spheric form. 





8 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


Additional lenses with Plane Mirrors.—Figure 6 .—Plate 2. 

The additional lenticular panes, having their common focus in 
the centre of the drum, are disposed in the form of a truncated 
pyramidal roof, and thus throw out, towards the heavens, eight lu¬ 
minous bodies of rays, which are reflected back on the horizon by 
the plane mirrors. This catadioptric accessory system is, besides, 
disposed with relation to the dioptric drum, so that the additional 
flashes precede the great flashes by some seconds. 

Catadioptric Rings.—Figures 7 and 8 .—Plate 2. 

In the smaller lenticular Beacons, called catadioptric , the zones 
of mirrors are replaced by rings with a triangular section. The 
rays emanating from the common focus are refracted at their en¬ 
trance into the triangle. They are afterwards reflected inwardly 
by the larger side, and escape by the third side while undergoing 
a second refraction. (1.) 

Large Reflectors with a spheric curve. 

When the maritime horizon of a dioptric lighthouse does not 
embrace an angular space of more than three-quarters of a circle, 
one or more Reflectors, with a spheric curvature, are usually 
placed in the sector which may remain obscured, in order to bring 
back to the focus the luminous rays which would diverge, and 
so be utterly lost on the land side. 

SECTION 2i 

FURNITURE OF THE LENTICULAR APPARATUS. 

The Furniture of Lenticular Lighthouses presents varied ar¬ 
rangements ; but it is deemed superfluous to describe those varie- 


(1.) The larger Side of the generating triangle of those glass rings presents out¬ 
wardly a convex curvature. The two other sides are one convex, and the other con¬ 
cave, and of the same line of curvature, so that the convergence produced by the first 
is compensated by the divergence resulting from the second. The effect would be the 
same if the two sides adjacent to the obtuse angle were right lines. The curvilinear 
form has been adopted merely as being more easy of execution than the rectilinear. 

The late improvements in the melting and cutting of glass have enabled us to under¬ 
take recently the construction of catadioptric apparatus of the third and even of the 
first order. 





CODE OF INSTRUCTION ON LIGHTHOUSES. 


9 


ties here, being generally of such simple construction as to be 
easily understood at first sight. This furniture is, moreover, of 
such solid workmanship as to require nothing more, usually, than 
to be kept clean. 


SECTION 3. 

MECHANICAL AND OTHER LAMPS, USED IN ILLUMINATING LIGHT¬ 
HOUSES AND LENTICULAR BEACONS. 

The Lenticular Lighthouses of the three first orders are illu¬ 
minated by Mechanical Lamps , whose socket is furnished with 
cylindrical concentric wicks to the number of two, three, or four, 
according as they are attached to apparatus of the third, of the 
second, or of the first order. 

For Beacons of the fourth order, are used ordinary Lamps, with 
a constant level, or Hydrostatic Lamps. 

Mechanical Lamps. 

The Mechanical Lamps of Lighthouses have all, for motive- 
power, a weight, whose cord is wound round an axis placed under 
the reservoir of oil. 

The transmission of the motion of the axis to the pumps allows 
of numerous combinations. We shall limit ourselves to the men¬ 
tion of the three systems actually in use, namely: 

1st. A Lamp with clock-movement , putting in play poeket- 
valves or Pumps. 

2d. A Lamp with peg-escapement , with pumps disposed as in 
the first system. 

3d. A Lamp with crooked Levers , communicating an alternate 
motion to the pistons of two bodies of pumps immersed in the 
reservoir. 

First kind Mechanical Lamps—Lamps loith Clock Work .— 

Figure 9 .—Plate 3. 

The mechanism of the Lamps of the first sort presents the ordi¬ 
nary arrangement of that of turnspits , and has for regulator a fly 
with wings. This mechanism transmits, by means of cog-work, 
a rotary motion to a vertical beam which passes through the re- 

2 


10 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


servoir of oil, and which rises to the height of the body of Pumps 
fixed on the corner of the bucket. The revolving beam commu¬ 
nicates, by means of a system of crank-work, or cogged wheels, 
an alternate rectilinear motion to the pistons of the pumps. 

Figure 10.— Plate 3. 

The body of Pumps comprises three or four chambers. 

The pockets or Valves are of sheep-skin, or some other soft 
and delicate leather. 

Figure 11 .— Plate 3. 

The suckers are generally of leather. Those of the old Lamps 
are cut into two strips, one for the lower orifices, the other for 
the upper ones. Each of those suckers, cut by means of a punch, 
is supported by a little tongue forming a hinge. 

Figure 12.—Plate 3. 

In the new lamps, the suckers are formed of round pieces of 
leather isolated in their chambers. 

The socket of the tube of a Lamp with manifold wicks is ad¬ 
justed, by means of a screw-level and round piece of leather, on 
the middle of the body of pumps. 

The most usual causes of derangement in the Lamps of this 
system are : 

1st. The irregularity or defective play of the suckers; inter¬ 
ruptions which most frequently happen through negligence in 
the cleaning. 

2d. The deterioration of the valves. 

3d. The defects in the motion of the fly. 

4th. The wearing out of the cogs of the wheels that turn the 
vertical beam which transmits the motion to the pumps. 

5th. Some derangement in the relative positions of the little 
cogged wheels to which are attached the Pistons of the Pumps of 
the greater part of the Lamps with clockwork-movement. 

Second species Mechanical Lamps—Lamps with Peg-escape - 

ment.—Figure 13 .—Plate 4. 

In the Lamps of the second sort, or Henry Lepaute’s Lamps, 
the motive axis supports a horizontal wheel furnished on the two 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


11 


sides of its border with small rollers perpendicular to its plane. 
These Rollers form an escapement with the,four sockets of angular 
levers, which transmit an alternate circular motion to two vertical 
beams which go through the reservoirs of oil. These beams com¬ 
municate, finally, by means of their upper arms, a rectilinear 
alternate motion to the pistons of four pumps. 

Figures 14 and 15 .—Plate 4. 

The body of those pumps is arranged as in the Lamps with 
clock-movement, with this sole difference, that the addition which 
surmounts it embraces a diaphragm pierced with a very small 
orifice, called the regulating hole . (1.) 

To the two first causes of derangement noticed in the preceding 
article, the two following are added in regard to the Lamp of 
Henry Lepaute : 

1st. The obstruction of the regulating hole, or its being too 
open. 

2d. Some change in the form or relative disposition of the 
pieces forming the escapement. 

This last change may be owing to the mere loosening of some 
of the screws, and especially of those which hold up the escape¬ 
ment-sockets. 

Third sort of Mechanical Lamps—Lamps with Crooked Levers .— 

Figure 16 .—Plate 5. 

In the Lamps with crooked levers, the motive axis is furnished, 
at one of its extremities, with a horizontal wheel working two 
pinions, on the fore part of each of which is fixed a crooked lever, 
which meets alternately two pegs fastened upon a vertical stem. 
This stem traverses, in a leather box, the bottom of the reservoir 
of oil, and carries to its upper extremity a large circular piston, 
which moves in a cylindrical pump wholly immersed in the oil. 

Each of the two pumps communicates, above and below, with 


(1.) This new system of Lamps, introduced some time after the publication of the 
instructions of 1835, has appeared preferable to that of the Lamps with clock-move¬ 
ment, and has been exclusively applied to lenticular Lighthouses of the three firs f 
orders established since 1837. 



12 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


a box with suckers, so as to produce a continued jet in the ascend¬ 
ing tube of the Lamp. 

This tube, or tunnel, has, in its upper part, immediately below 
the level, a diaphragm pierced with a little orifice, as in the Lamps 
of the second sort. 

The principal causes of derangement in Lamps with crooked 
levers are: 

1st. The obstruction or the excess of aperture of the regulating 
hole. 

2d. The defect or the excess of play of the stems of the pistons 
in their leather boxes. 

3d. The deterioration of those Pistons. 

4th. The thickening of the oil in the pump and in the chambers 
of the suckers for want of cleaning. (1.) 

General Observations on Mechanical Lamps. 

The Mechanical Lamps used in the service of Lighthouses of 

the three first orders should, whatever may be their composition y 
raise, in a given time, four times the quantity of oil consumed 
during the same time—that is to say : 

gramm. * *kil. 

For the 1st order. 4 X 750 ~ 3,000 per hour. 

2d . 4 x 500 = 2,000 - 

3d . 4 x 190 — 760 - 

This triple superabundance is necessary in order that the socket 
may not become heated beyond the proper degree. If, on the 
other hand, it exceeded the quadruple, it would be with some 
difficulty that the flame could be raised to the due height, unless 
by raising the wick above the fixed limit, which operation would 
displace the focal point. 

The burning of the Lamps with clockwork-movement is regu¬ 
lated by modifying suitably the inclination of the wings of the 
fly, and the motive weight. 


(1.) Lamps with crooked levers have had but a very limited application, and it is 
probable that before long their use will be completely abandoned, especially in conside¬ 
ration of the chances of derangement particularized under numbers two and three. 

* One and one-sixteenth of a quart nearly. 












CODE OF INSTRUCTION ON LIGHTHOUSES. 


13 


In the new Lamps, where the oil escapes through a small uni¬ 
form orifice, the keeper has no other means of modifying, for more or 
for less, the product of the pumps than to increase or diminish the 
motive weight; and it is conceived, moreover, that this product 
will be so much the more uniform as the orifice shall be reduced 
in size and the charge increased. 

But the volume of oil used by the socket of Lamps of this kind 
depends not altogether on the motive power and on the section 
of the regulating hole. It has been ascertained, in fact, that the 
product of the pumps increased by nearly one-half, after some 
hours of combustion, on account of the diminution of clot which 
the oil experiences in becoming heated. 

The inference to be deduced from this fact is, that, in order to 
avoid the necessity of modifying the motive weight during the 
night service, it would be requisite that the Lamp be regulated so 
that its expenditure, when cold, might be little less than two- 
thirds of the stated product, or the eight-thirds of the consump¬ 
tion of the socket. (l.) 

According to the 25th article of the Code of Instruction, pub¬ 
lished in 1835, on the service of lenticular Lighthouses, the 
heights to which the flame of the mechanical Lamps of the three 
first orders should reach have been respectively fixed, as follows: 


For the 1st order. 10 to 11 centimetres. (2.) 

2d.. 8 to 9 - 

3d .. 7 to 8 - 


We succeed in obtaining this developement, and in retaining it, 
by suitably regulating the height of the wicks and the curve of the 
glass chimney, as also the aperture of the iron pipe which sur¬ 
mounts this chimney. 

The wicks are raised gradually during the first hours of com¬ 
bustion up to 7 millimetres above the socket, a point beyond which 
they ought very rarely and very sparingly pass. 


(].) The addition of a regulating cock appears to offer the most simple means of 
modifying, at will, the product of the pumps in Lamps of this kind, and we have re¬ 
cently caused to be introduced this new article into a Lamp whose mechanism has 
otherwise been very much simplified. Experience will show' whether the advantages 
which the cock appears to promise will effectually overbalance the inconveniences 
which its use may present. 

(2.) A ceniimetre is equal to part of an inch, English measure. 









14 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


In raising the curve of the chimney, t!ie developement of the 
flame is increased ; but it assumes a reddish tint if a certain limit 
be passed. 

The developement of the flame is checked, and it becomes whiter 
by lowering the chimney. 

By turning to the right or left the moveable holder which sup¬ 
ports the chimney, we lower or raise it. 

Figures 17 and 18.— Plate 5. 

The disposition of the sockets in the new Lamps accommodates 
itself very well to this operation. But with the old mechanical 
Lamps, whose glass-holder is confined by the screw-collar that 
supports the socket, we must first unfasten this collar, then hold 
the socket in order to avoid unscrewing the levelling-screw while 
turning the glass-holder round. 

Figure 9 twice.—Plate 3. 

The operation of the pipe is that to which we have the most 
frequently had recourse. When the key is turned, the flame in¬ 
creases in volume and diminishes in whiteness. The contrary 
operation produces a contrary effect. 

Central point of the Lamps in Lenticidar Lights. 

In order that a lenticular apparatus should be suitably lighted, 
it is essential, as far as concerns the lamp employed : 

1st. That the axis of the socket of such lamp coincide with 
the axis of the apparatus. 

2d. That the upper part of said socket be on a level with and 
facing the focal plane. 

Of 28 millimetres for the 1st order. (1.) 

Of 26 - for the 2d - 

And of 24-for the 3d - 

The Code of Instructions for the use of the keepers of lenticu¬ 
lar Lighthouses thus describes the different operations by which 
the position of the Lamp is regulated : 

1st. The position of the centre of the apparatus is determined 
by means of two threads stretched diametrically through the 
middle of the four uprights of the frames of the Lenses. 


(1.) A millimetre is equal to part of an inch, English measure. 









CODE OF INSTRUCTION ON LIGHTHOUSES. 


15 


2d. A wooden gauge, adapted to this purpose, is fitted on the 
socket, and the centre of the gauge is plainly marked out. 

3d. By means of the grooves of the tripod, the Lamp is brought 
to nearly a suitable height, or, if there should be only a difference 
of 10 to 15 millimetres at most, the screws alone are put in play. 
We next place on the rim of the socket a small level with air- 
bubbles, and, according to its indications, the lamp is lowered until 
the upper part of said socket becomes horizontal. 

4th. In order to centralize the socket, that is, to make the 
middle of the gauge correspond with the point where the two 
threads cross each other, the upper nuts of the lowering screws 
are unfastened, and the lamp is displaced, horizontally, as far as 
is necessary to reduce it to the suitable position. 

5th. Finally, the small level is replaced on the rim of the 
socket, and, if we ascertain that it is not horizontal, it is brought 
back to that position, taking care, at the same time, to satisfy the 
two first conditions relative to the centrage and to the height. 

In the lenticular apparatus of the third order, (small model,) 
such as those at the mouth of the Loire, the tripod on grooves is 
replaced by a moveable platform, which is raised or lowered by 
means of a crank. 

In order to facilitate the superintendence of the Keepers, an 
Alarum-Bell is fitted to the Lamps used in lenticular Lighthouses. 
The escapement of this mechanism is retained by the end of a 
lever bearing, at its other extremity, a small cup pierced with a 
little hole. This vessel is placed under the drainer of the socket, 
and, as long as it is kept full of oil, it sustains its counterpoise; 
but if the ascension of the oil should stop, the vessel is emptied, 
the counterpoise descends, and the alarum-bell, freed from its 
confinement, begins immediately to play. 

Lamps with a constant Level.—Figure 19 .—Plate 6. 

Lamps with a constant level are so extensively used that it is 
almost superfluous to describe them here. It is known that their 
reservoir, furnished with a valve, is lodged in the body of the 
Lamp; and, at the moment the valve touches the bottom of this 
second vessel, it rises, and thus establishes a free communication 
between the reservoir and the socket. 

It is necessary, in order that those lamps be regularly fed : 


16 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


1st. That the extremity of the lower spout of the reservoir be 
depressed some millimetres below the rim of the socket. 

2d. That the external air should have free access to the low r er 
orifice of the said reservoir in order to replace the oil as fast as it 
is consumed. 

The sockets of the Lamps with a constant level, employed in 
lighting the catadioptric apparatus, present, generally, the ordinary 
arrangement of sockets with a double current of air, and are capped 
with a curved chimney. (1.) 

Figure 20 .—Plate 6. 

They differ particularly from the ordinary sockets in the fol¬ 
lowing relations : 

1st. The wick-holder is independent of the socket in which it is 
encased. It is formed of two small concentric Caskets of open 
work, between which the wick is adjusted without the addition 
of any mechanism to raise or lower it. 

2d. The chimney, of nearly a cylindrical form, is supported, a 
little above the socket, by a moveable glass-bearer. 

To facilitate the centrage m the apparatus in question, the Lamp- 
sockets have been mounted on a lateral tube passing into a leather 
box, an arrangement which allows of their being displaced either 
vertically or horizontally. 

Experience has shown that sockets entirely of copper flatten] 
are not good for use. 

Before the expiration of a year’s service, it frequently happens 
that the rim becomes notched. Thence, the relation of Level be¬ 
tween the edge of this rim and the lower orifice of the reservoir 
being altered, the oil overflows by a continued motion. 

To obviate so grievous an inconvenience, we have lately sub¬ 
stituted wrought iron tubes for copper ones in the construction of 
sockets for Lamps with a constant level destined for the lighting 
of Catadioptric Beacons. 

Some extra sockets are always sent with those Lamps ; but, al¬ 
though the operation is very simple, and consists merely in un- 


(1.) Sockets of that sort called d la Bordier-Marcet have been applied to some Lamps 
of catadioptric apparatus, and are still used (1842) for the two Beacons of Pertuis- 
Breton. 



CODE OF INSTRUCTION ON LIGHTHOUSES. 1? 

soldering one socket and replacing it by another similar piece, it 
has been very generally executed in an awkward manner by the 
tinmen to whom it has been entrusted in the departments. 

It is with a view to prevent those blunders that, in the Lamps 
lecently manufactured, the tube that feeds the socket is fastened 
to the neck of the body of the Lamp by a screw and leather ring. 

Figure 21.— Plate 6. 

The moveable gallery, in which is fitted the foot of a glass chim¬ 
ney belonging to a Lamp with a double current of air, is usually 
formed of two concentric glass-holders. It embraces the socket 
wi f h a gentle friction, and this friction is increased at pleasure by 
slightly bending inward, with flat pincers, the elastic plates of the 
inner glass-holder. 

The wick, very exactly cut, should be kept 6 or 7 millimetres 
above the socket. If this height were exceeded, a greater de- 
velopement w r ould, for the moment, be given to the flame; but 
soon the contrary effect would be manifest, seeing that the wick, 
being reduced to tinder, would lose its capillary action. 

The height of the flame, answering to the complete effect of 
Lamps of this sort, is from forty to forty-five millimetres. It is 
obtained by raising to the due point the moveable gallery which 
supports the glass chimney. If this point be passed, the flame 
will become reddish, and will probably smoke. If we err on the 
other extreme, it will remain white, but without attaining the 
proper developernent. 

In order that the most brilliant part of the flame correspond to 
the principal focus of the glass rings, it is requisite that the axis 
of the socket should coincide with the axis of the apparatus, and 
that the upper part of this same socket should be from 20 to 22 
millimetres in opposition to the middle plane of the central ring. 

The Keepers of the Catadioptric Beacons have ordinarily no oc¬ 
casion to trouble themselves about the cenlrage of the Lamp with 
a constant level, as its position is determined by that of the hooks 
by which it is suspended. However, as it may happen, after the 
repair or renewal of those Lamps, that the socket may be found a 
little out of place, it then becomes essential to verify the centrage . 

In order to render this verification easy, there are fixed, on the 
3 


18 CODE OF INSTRUCTION ON LIGHTHOUSES. 

four uprights of the catadioptric apparatus recently manufactured, 
certain small buttons, serving to confine diametral threads, as in 
the apparatus of the higher orders. 

Two models have been adopted hitherto for the socket of the 
Lamps in question : one of 24 and the other of 22 millimetres in 
diameter, measured by the middle of the annular space occupied 
by the wick. 

The consumption of oil is valued, on an average, at 60 grammes 
per hour for the large socket, and at 45 grammes, for the small. 

Lamps with a constant Level and double Wick. 

The application of a socket with a double wick to those Lamps 
with a constant level, has been, for sometime, successfully tried at 
the beacon of Alpreck, as also at the provisionary Lighthouse of 
the Sables d’Olonne. 

This socket, of a bore inferior to that of the Lamps of the third 
order, consumes about 115 grammes of oil per hour. Its use dif¬ 
fers from that of the ordinary sockets only in this, that during the 
first hour of combustion, the developement of the flame should be 
conducted more slowly. 

Figures 22 and 23 .—Plate 7. 

To the Catadioptric Beacons, disposed so as to illuminate their 
whole horizon, has been applied the Hydrostatic Lamp with sul¬ 
phate of zinc, called the Thilorier Lamp, from the name of its 
inventor. 

This Lamp comprises two reservoirs: the one, higher, filled 
with liquid sulphate of zinc, and the other filled with oil of 
Colza. 

The specific weight of the first liquid is fixed at one and a half 
times that of the second. 

A syphon springing from the bottom of the upper reservoir, and 
terminating a little above the bottom of the oil-vessel, establishes 
the communication between them. 

v t 

A similar tube springing from the lid of the lower vessel and 
terminating at the socket of the Lamp, serves to cause the oil to 
rise. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 19 

The licl of the upper reservoir is traversed by an open tube en¬ 
veloped in a leather box. 

This regulating Tube is to be brought down to such a level, 
that the column of sulphate of Zinc, immediately below this level, 
may equipoise the column of oil floating on a level with the rim 
of the socket. 

As the oil burns, the air is introduced by the regulating tube, 
and comes to occupy the summit of the upper vessel, as in the 
common lamps with a constant level. There is, however, this 
essential difference, that the permanency of level during the com¬ 
bustion, does not exist in hydrostatic lamps of this sort. In fact, 
in proportion as the sulphate of Zinc takes the place of the oil in 
the lower vessel, in the same proportion the two liquid columns 
shorten, and thence their primitive ratio of 2 to 3 would be found 
altered, if it were not unceasingly restored, during combustion, 
by the gradual sinking of the oil below the rim of the socket. 

It is in order to remedy as much as possible this want of level 
that so large a diameter has been given to the lower reservoir. 
The regulating tube has, moreover, been fitted into a leather box, 
so that the keeper may be able at need to raise the oil even with 
the socket, in easing this tube of a quantity nearly equal to two- 
thirds of the depression. But, this corrective may be dispensed 
with, even during the longest nights, when the Lamp is in good 
order, and the oil and wicks are of good quality. 

Figures 23 and 24 .—Plate 7. 

In order to furnish a TJiilorier Lamp with oil, its socket is 
capped with a funnel, which communicates only with the interior 
of this lamp, and presents the height required, in order that a 
column of oil, level with its cistern and terminating at from 4 to 5 
millimetres above the bottom of the lower reservoir, should be 
equal to a column of Sulphate of Zinc rising to the lid of the up¬ 
per reservoir. The wick should be kept at from 7 to 8 milli¬ 
metres above the socket, and the flame when fully developed, is 
kept up at a height of from 45 to 50 millimetres. 

The chimney is supported by a revolving gallery which is 
raised or lowered by means of a nut screw. 


20 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


Figure 25 .—Plate 7. 

In order to remove these Lamps from place to place without 
being exposed to the chance of spilling the liquid, the orifice of 
the regulating tube is closed by a small peg of soft wood, and the 
socket is capped by a lid fitted inwardly, as the foot of the funnel 
was. 

The position of the socket of a hydrostatic Lamp in the appa¬ 
ratus it is intended to light up, may be set down at from 24 to 25 
millimetres below the focal plane. 

This Lamp rests upon a moveable platform, whose motion is fa¬ 
cilitated by a counterpoise. A stay is so disposed as to fix this 
system at a suitable height, so that the apparatus being once ar¬ 
ranged, we may have no more trouble about the centrage. How¬ 
ever, it is right to verify it from time to time, especially after there 
has been a change or even a mere renewal of the Lamps. 

Like all apparatus of this kind, the Thilorier Lamps are subject 
to obstruction in their tubes. To obviate this inconvenience, care 
should be taken to rinse them every six months with boiling ley. 

It is essential to ascertain, at the end of a certain time, whether 
the sulphate of Zinc preserves a specific gravity exactly equal to 
once and a half that of Colza oil. For this purpose, the Lamp is 
entirely emptied into a vessel of sufficient capacity, the oil is bottled 
off, and we plunge into the saline liquid an areometre, which 
bears a peculiar mark answering to the density required. 

If the density is too great, pure water is added until the mark 
of the areometre sinks to the surface of the liquid. If, on the 
contrary, the liquid sulphate is too thin, its weight is increased by 
the addition of the necessary quantity of dry sulphate. 

The diameter of the socket of the hydrostatic lamps used in 
lighting catadioptric beacons is 21 millimetres: a dimension an¬ 
swering to the middle of the annular space occupied by the wick. 

The consumption of oil rises to the average of 55 grammes per 
hour. 

SECTION 4. 

ROTARY MACHINES OF THE LENTICULAR APPARATUS. 

The Rotary Machines of the new Lighthouses and Beacons pre¬ 
sent the ordinary combinations of clockwork-movements, except 
in so far as regards the regulator. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 21 

Figure 26 .—Plate 8. 

The horizontal disposition has been applied hitherto to the ma¬ 
chines of the revolving apparatus of the 1st and 3d order. The 
wheelwork has been superadded in machines of the 2d and 4th 
orders, in order to reduce to a minimum the volume of the me¬ 
chanism. 

Figure 27 .—Plate 8. 

Th e flys of the machines of the three first orders comprise three 
distinct parts. 

1st. Two regulating Balls. 

2d. Two moveable wings which are developed by the swerving 
of the Balls. 

3d. Two upper wings, called fixed, whose inclination can be 
varied at will. 

The swiftness of the rotary motion may be modified in certain 
limits, by raising or lowering the regulating balls upon their 
stems, as w T ell as by modifying the inclination of the fixed wings 
of the fly. 

In order that a rotary machine may perform its functions regu¬ 
larly, it is essential that the axle of the fly be exactly perpendicu¬ 
lar, and that its adjustment afford some play in the vertical way. 

It should be further observed, in fixing the motive machine of a 
Lighthouse, not to indent the wheel which communicates motion, 
with the wheel of the moveable apparatus, beyond the degree of 
depth adapted to the form of their cogs. 

It is, finally, very essential that the principal support of the 
apparatus should be invariably established in such a position, that 
the platform upon which the circular car of the moveable appa¬ 
ratus rolls, should be perfectly level. 

When this platform begins to incline through some defect in 
the construction upon which it rests, it is necessary in order to 
restore its level, to raise to a proper point, the column or candela¬ 
bra, which serves as a support to the system of the lenticular 
Apparatus. 

This raising can be effected, in lighthouses of the three first 
orders, by the aid of steel wedges driven under the base of the 
concave column which supports the candelabra, allowing, how¬ 
ever, sufficient play in the adjustment of the foot of the stem of 
the candelabra, with the head of said column. 


22 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


In the contrary case, it would be requisite, in order to rectify 
the want of level, to take down and set up the entire apparatus. 

CHAPTER II. 

CATOPTRIC LIGHTHOUSES AND BEACONS. 

SECTION 1. 

COMPOSITION OF THE REVERBERATING APPARATUS. 

Figure 28.— Plate 9. 

The Catoptric Apparatus still used on the coasts of France for 
the illumination of some old Lighthouses, are formed of parabolic 
reflectors, at the focus of each of which is placed the socket of a 
Lamp with a constant level. 

Figure 29.— Plate 9. 

If it be a Lighthouse with a fixed light, the reverberating lights 
are placed circularly upon one or more ranges so as to distribute 
their light, with as little inequality as possible along the extent 
of the maritime horizon which they are to illuminate. 

Figure 30.— Plate 9. 

If it be an apparatus with a changing light, the reflectors are 
usually grouped on the three or four faces of a revolving appa¬ 
ratus. 

Figure 31.— Plate 9. 

Bordier Marcet has executed, for some lighthouses, reflectors 
with a double parabola. They are formed by the union, upon 
one same axis, of two parabolic furnace-bottomed reflectors, hav¬ 
ing their focus 55 millimetres apart, and are lighted by a lamp 
with two sockets. 

These reflectors by reason of their divergence offer the ad¬ 
vantage of a display of brilliancy much greater than that of simple 
reflectors; but, on the other hand, they give place to a greater 
loss of light. 

Figure 32.— Plate 9. 

The same artist has invented, for lighting the entrances of har¬ 
bors, reverberators called star-lights , which present two reflec- 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


23 


tors produced by the revolution of a parabola revolving round the 
ordinate corresponding to its focus. 

This arrangement produces an equal distribution of the light, and, 
by attaching tangent-wise two demi-paraboloides produced by the 
same parabola revolving round its axis, a flash more vivid is pro¬ 
jected in two directions. 

The reflectors of the old Lighthouses of France, as well as the 
greater part of the sidereal reverberators, have been simply plated 
over, and consequently require frequent repairs. But, at present, 
the apparatus of this kind are made of copper, inlaid with silver, 
sufficiently thick to ensure them to last a long time. 

SECTION 2. 

LAMPS WITH REVERBERATING APPARATUS. 

The Lamps of Catoptric Apparatus are all of a constant level. 
Their sockets are, besides, of two sorts : the first with a curved 
chimney, and, the second, with a straight one. (1.) 

The sockets of the first sort, are in everything similar to the 
ordinary Argand ones, of which we have made mention before, in' 
the article concerning Lamps with a constant level, for lighting 
small lenticular apparatus. 

The sockets with a straight chimney differ from the curved in 
the following particulars :— 

1st. The wick, instead of being fixed at its lower edge, on a 
ring which is raised or lowered by the aid of a little crane, is 
loose in a double wicker basket, from which it projects 5 or 6 
millimetres. 

2d. The chimney, of a form nearly cylindrical, is supported at 
about 12 millimetres above the socket, by two elastic rings fixed 
against a vertical stem which is fastened to its foot in a socket 
soldered to the tube. 

The wick, cut according to a pattern, is introduced by means of 
a wooden tube or barrel into the wick-holder, then pushed to the 
bottom. 


(1.) We might mention a third species, as the old Beacons of Havre, of Port-Ven- 
dres, and of Cette, which are still lighted by burners with a flat wick, and without- 
glass chimneys. But those reflectors, imperfect as they are, will soon be replaced by 
lenticular apparatus. 






24 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


In order to raise the wick, when it requires to be snuffed, a 
little bodkin might be used. After being snuffed, it is raised again 
very regularly 7 or 8 millimetres above the edge of the wick- 
holder, then it is brought back to the fit point by the aid of the 
regulating stopper, or trimmer. This utensil, disposed like a 
cylindrical wicker cap, is of such depth, that when its edge rests 
on the wick-holder, the bottom is on a level with the top of the 
wick regularly adjusted. 

The Sockets with a straight chimney, called a la Bordier-Mar - 
cet , exhibit not so beautiful a developement of flame, as the ordinary 
Argand burners : But, the service of the first is, in some respects, 
more simple and more easy than that of the second. 

SECTION 3. 

ROTARY MACHINES OF THE REVERBERATORY APPARATUS. 

The Rotary Machines of the old Catoptric Lighthouses, with 
eclipses, still existing on the shores of France, differ particularly 
from those now in question, in this, that, in place of a simple fly 
they have a pendulum as regulator of their motion. 

This latter arrangement gives more exactness in the division 
of time ; but we can easily obtain, by means of flys with balls, the 
degree of precision required for the application in hand, and they 
present, over the oscillating pendulum, the essential advantage of 
a continued motion. 

The Machines of the two old Lighthouses of Cape Frehel and 
of the Baleines, comprise, independently of the pendulum, an addi¬ 
tional mechanism, with a motive weight and fly, in order to regu¬ 
late the play of the escapement. 

SECOND SECTION. 

ORGANIZATION OF THE SERVICE OF LIGHTHOUSES. 

The organization of the service for illuminating Lighthouses 
may be considered under the triple head of the Materiel , the 
Personnel , and the mode of administration. 

Two Systems of Administrative Organization. 

Since the first of July, 1839, two modes of administrative organi¬ 
zation are comparatively applied to this service. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


25 


On the coasts ot la Manche in the extent comprised between 
the frontier of Belgium and the department of the Cotes-du-Nord, 
the lighting is done by administration, except what regards the 
supplies of oil. 

For the two other great divisions of the sea shore, contracts 
have been renewed. 

It is conceived that, in the first system, the action of the Engi¬ 
neers and Conductors is more direct, and that their intervention 
must be more frequent. 

We could not, without digressing from our principal object, 
compare together these two organizations, and we shall conse¬ 
quently limit ourselves, in this second section, to consider the ser¬ 
vice of maritime illumination under the two heads of the materiel 
entrusted to the Lighthouse Keepers, and of the personnel of 
those agents. 

In what follows, there will only be question of the lenticular 
Lights, as, from the explanations relative to their use, one may 
easily deduce what may be applicable to lights with reflectors. 

CHAPTER I o 

MATERIEL. 

The principal points to be considered in the organization of the 
service of Lighthouses, as regards the materiel , may be summed 
up under the five following heads : 

1st. Fitting up ^L an terns and Apparatus for lighting. 

2d. Keeping up 5 

3d. The assortment and Preservation of the furniture and Uten¬ 
sils necessary for lighting and for cleanliness. 

4th. Supplies of oil, wick, chimneys, Linen, &c. 

5th. The furnishing of the Buildings. 

SECTION 1. 

FITTING UP OF THE LIGHTHOUSES AND BEACONS. 

The fitting up of the apparatus for lighting, and that of their 
Lanterns, embraces numerous details, which are not, in many re¬ 
spects, in the line of this summary instruction. There are, how¬ 
ever, some of these details, to which we have thought it right to 
4 


26 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


call attention, particularly to that which concerns the arrange¬ 
ment of the upper part of the buildings. 

The lenticular apparatus of the three first orders cannot be fitted 
up upon a plain floor. They should rest upon a vault of masonry, 
in which is contrived, laterally, an opening for the passage of a 
winding staircase leading to the chamber of the Lantern. 

When we have to fit up a Lighthouse of the first or second 
order, of more than 20 metres in height, it is necessary to con¬ 
struct under the chamber of the Lantern, another, called the ser¬ 
vice chamber. This contains one or two beds, upon which the 
keepers repose in their turn, while waiting for their watch. 

The Catadioptric Beacons are commonly placed on the newel 
of the staircase of their turret. The Lanterns of most of the 
Lighthouses are clamped, at their feet, on a circular basement 
whose diameter and height should be in proportion to the dimen¬ 
sions of the Lantern and Lighting-apparatus. 

The following table indicates the diameters of the lenticular 
apparatus of different orders, as also the principal dimensions of 
the Lanterns and of their basements. (I.) 


LENTICULAR 

APPARATUS. 


Diameter in Number of Diameter in 



LANTERNS. 


the work. 

l m ,84 

1,40 

1,00 

0,375 

0,30 


panes. 

16 

12 

10 

S 

8 


the work. 


Height of 
glass work. 


3 m ,50 
3,00 
2,50 
1,60 
1,40'} 
to 
L60 J 


3 m ,00 

2,55 

1,90 

1,10 

0,90 

to 

1,10 J 


BASEMENTS OF THE 

LANTERNS. 

Diameter in 

the work. 

Height in 

the work. 

3 m ,20 

2 m /20 

2,70 

2,10 

2,25 

2,00 

1,40 

0,90 

1,291 

1 


1 

to 

0,90 

1,40 J 



(1.) To complete these summary remarks, we have marked upon plate 10, hereto 
annexed, cuts of the upper part of the four sorts of Lights, hereafter designated. 

Figure 33.—Plate 10.—Light of the 1st order, with Eclipses. 

Figure 34.—Plate 10.-2d order, with fixed Lights. 

Figure 35.—Plate 10.-3d order, with a Light varied by flashes. 

Figure 36.—Plate 10.-4th order, (small model,) with fixed Lights, 



































CODE OF INSTRUCTION ON LIGHTHOUSES. 


27 


The chambers of the Lanterns should be sufficiently airy, and at 
the same time impenetrable to the rain. 

Ventilation of the Chambers of the Lanterns. 

Ventilation is necessary for two reasons. First, it purifies the 
interior of the Lanterns, and secondly, it prevents or diminishes 
the aqueous precipitations on the interior face of the glasses, pro¬ 
duced by the current of ascending air which always prevails in 
high towers. 

Various arrangements may be adopted in order to arrive at this 
result. One of the best understood appears to be that which has 
been applied to some Lighthouses in Holland. It consists in 
opening, in the basement of the Lantern, two rows of ventilating 
holes, the one from 20 to 30 centimetres above the floor of the 
chamber, and the other in the crown-work. These last, being of 
a diameter from 5 to 6 centimetres, open inwardly by a vertical 
turn at the very foot of the Lantern, so that independently of the 
office of ventilators, they perform, when wanted, that of gutters 
for the discharge of the water, which, in damp weather, runs 
along the glasses. The lower holes are closed at will by copper 
caps, and the upper holes by simple wooden stoppers. The Lan¬ 
terns of some Lighthouses on our southern coast are aired by a 
simple range of ventilators, from 8 to 10 centimetres in diameter, 
open at 40 to 60 centimetres opposite the top of the basement walk 

If it is found that the chimney of a Lantern does not offer the 
necessary outlet for a good ventilation, the defect might be reme¬ 
died by the addition of two or three chimneys with an air- 
draught. 

Each of these chimneys should be formed of the end of a tun¬ 
nel-pipe pierced with holes at its upper edge, and should be 
capped with a hollow ball, equally pierced with holes at its lower 

part. 

This system appears preferable to that of the revolving caps 
which are too apt to lose their pliability. 


Precautions against the Formation of Dust. 

The dust which gathers or penetrates into the chambers of Lan¬ 
terns is one of the most active agents in damaging the apparatus 


28 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


of the old, as well as of the new System. It is extremely im¬ 
portant, therefore, to prevent or, at least, diminish as much as 
possible the formation of this dust. 

In order to this, it may be very useful: 

1st. To cover with Lead, with brass plates, or marble the floor 
of the chambers of the Lanterns. 

2d. To cover with Zinc, stucco or marble the partition of the 
basement wall, or at least, to cover it with several coats of oil- 
paint, frequently renewed. 

The plastering on the frames of the Lighthouse-staircases, often 
produces by its crumbling a flinty dust which the current of as¬ 
cending air is incessantly conveying into the upper chambers. 
It were to be wished, that the most of this plastering were done 
over in Roman cement, and coated with oil-paint. 

SECTION 2. 

ON THE PROPER KEEPING OF THE LANTERNS, AND LIGHTING- 

APPARATUS. 

The penetration of rain-water into the Lanterns is prevented 
by due care bestowed on their soldering, cementing, painting and 
glazing. 

The operation of glazing the large Lanterns is amply enough 
described in the Code of Instruction on the service of lenticular 
Lights, (art. 78,) so as to enable a handy and intelligent keeper 
to replace the glasses without any assistance from others. How¬ 
ever, it will be generally advisable to entrust this work only to a 
glazier or Looking Glass manufacturer. Moreover, it will be in¬ 
dispensable to watch particularly : 

1st. That in putting in the glasses they be kept detached from 
their frames by means of small pieces of Lead, so as not to be ex¬ 
posed to the danger of being broken in storms, by the vibration 
of the Lantern. 

2d. That not less than from 2 to 3 millimetres in breadth be 
given to the horizontal joints of the glasses placed on top, in order 
that they be well cemented. 

All the visible iron work of the Lanterns should be carefully 
covered with abundant coats of oil-paint. White, or a greyish- 
$vhite, would appear to be the preferable colour, at least in the 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


29 


interior part, as it compels the keepers to pay due attention to 
neatness. 


Keeping in order the Apparatus for Lighting. 

The Code of Instruction for the use of Lighthouse keepers 
should be consulted on the subject of details relative to the keep¬ 
ing in order the Lighthouse Apparatus. We shall only remark 
here the points to which investigation should be particularly 
directed on visiting a Lighthouse. 

It cannot be too often repeated that, extreme neatness in keep¬ 
ing up all the parts of the lighting apparatus is the indispensable 
condition for their working well, and lasting long. 

For the optic pieces of the different apparatus, spirits of wine, 
English rouge, soft linen, and kidskin suffice for the ordinary 
cleaning. 

The glasses of the lenticular panes, as also the metallic reflect 
tors should never be washed or rubbed without first being dusted 
carefully. For want of this precaution they are liable to be 
scratched. 

Spirits of wine are especially used for cleaning the lenses of 
glasses. After having washed, by means of a small piece of 
Linen dipped in this liquid, the surface to be cleaned, it is first 
wiped with a soft dry linen, then it is rubbed with kidskin pow¬ 
dered or not with English rouge, but free from all dust of a nature 
to injure the polish of the glass. This skin should be equally 
free from every grease spot. 

Rouge in cakes (1,) of the suitable sort for polishing glass, 
cannot be applied to this use, and still less to the cleaning of sil¬ 
vered reflectors, without first having undergone a preparation 
which the keepers too often neglect, or execute badly. 

It is explained in detail in the Code of Instruction on the ser¬ 
vice of Lenticular Lights (art. 71) and consists in extracting the 
subtilest parts of the polishing rouge, in diluting it in water, and 
pouring it off at the end of some moments, as is done in the pre¬ 
paration of cobalt blue. 

(1.) Tritoxyde of Iron, or ferrique oxyde, commonly called English rouge. It is 
obtained by the calcination of the proto-sulphate of commercial Iron. This oxyde, 
according to the mode of preparation and degree of thinness, assumes various colours 
from the deep brownish red to the orange red. The oligiste Iron, which has the first 
tint, has too much acid to be used for this purpose. 






30 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


The liquid rouge thus obtained to the suitable degree of line¬ 
ness, is applied as a light painting, on the surface to be cleaned 
and polished. As soon as it is dry, this surface is rubbed with 
kidskin, as has been just mentioned. 

The application of English rouge on the glass pieces of the 
lenticular apparatus should not be repeated more than 3 or 4 
times a year, unless the dullness in their polish require for some 
time more frequent rubbings. 

Washing with spirits of wine, and rubbing with kidskin are 
sufficient for the common use of Lenses and tinned mirrors. 

As to metallic reflectors, they should be rubbed with rouge as 
often as their polish requires it. It is, besides, necessary to rub 
them daily with kidskin, after having dusted them, and taken out 
all the grease spots. (1.) 

Keeping and Preservation of Mechanical Lamps. 

The keeping up of the mechanical Lamps calls for the most 
constant attention. 

In order that they be kept in good condition for service, it is 
requisite 

1st. That they be cleaned carefully in all their parts, and par¬ 
ticularly in their pumps when they are taken off the apparatus. 

2d. That they be changed every fortnight in order that each of 
the three equipages of this sort, composing the ordinary assort¬ 
ment of a Lighthouse may not remain longer than one month out 
of use. (Art. 42, Code of Instruction, 1835.) 

The ordinary keeping of the Mechanism of the different sorts 
of Lamps employed in illuminating Lighthouses is reduced to the 
two following operations : 

All the pieces soiled with old oil are first wiped with a soft 
linen, and then cleaned with a small hand brush : using a little 
olive oil or watchmakers’ oil, in order to take off the grease more 
easily. 

There is next applied, with a little wooden spatula, watchma¬ 
kers’ oil to the necks of the pivots (as also to the rollers in the 


(1.) This skin should be soft and very pliant. Preserved with care from damp and 
dust it will last many years. The more it is impregnated with the polishing rouge the 
more efficaciously it acts. It may be washed in pure water without losing its supple¬ 
ness. However, recourse should never be had to washing kidskin, except in the case 
<pf its becoming sullied by some earthy substance. 




CODE OF INSTRUCTION ON LIGHTHOUSES. 


31 


mechanism with escapements) and then those pieces are made to 
revolve so as to help the penetration of the oil into their inter¬ 
stices. 

At the end of a few moments the pivots and interstices are com¬ 
pletely washed, and nothing more is required than to wipe them 
anew, in order to remove the superfluous oil. 

We must not omit to include in those applications of watch¬ 
makers’ oil, the axis of the pully of the moving weight. 

According to article 47 of the Code of Instruction for 1835, 
the mechanical Lamps of the Lighthouses should be taken down 
to be thoroughly cleaned every six months ; but this injunction 
has some exceptions. It is, in fact, thought that such an operation, 
frequently repeated, may become an active cause of deterioration, 
in unskilful and awkward hands. It is therefore essential that 
these dismountings of Lamps should not occur often without ne¬ 
cessity. When recourse must be had to them, all the pieces 
which can be reached in cleaning without being separated, should 
be left in their places. 

If it be a clockwork-movement, it can be withdrawn from its 
cage, all mounted, and cleaned, in the manner above mentioned, 
without disturbing its wheelworks. 

When it is necessary to clean thoroughly the pieces of the 
mechanism of a Lamp with an escapement or pegs, its dismount¬ 
ing may be limited to the taking away of the axis, an operation 
which is performed by previously dismounting the cock , or sup¬ 
port, which is in front of the key or crank. 

The use of the tripoli (a sort of red chalk) for the cleansing of 
the mechanisms may have bad consequences; for a few particles 
of this substance remaining in the interstices are sufficient to rust 
the pivots. It is advisable therefore to confine ourselves to watch¬ 
makers' oil , for cleaning, and to consider as null the first paragraph 
of article 48, Code of Instruction, for 1835. 

The first manuscript Instructions prescribed having a lamp in 
reserve constantly supplied with oil and wicks, and making it per¬ 
form one or two hours every day, so that it might be always ready 
to replace the Lamp in use. 

But experience has shown, that these apparatus, thus kept full 
of oil, which is not renewed daily, soon become pitchy, and may 
be unfit for use, at the very moment when wanted. 


32 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


It is to be remarked, in regard to the new Lamps with crooked- 
levers, or escapements, that we must avoid putting them in play 
when dry, with their motive weight, for fear of damaging them. 

SECTION 3. 

MOUNTINGS, UTENSILS, AND VARIOUS OBJECTS. 

The mountings, utensils, and various necessary implements, as 
well for the service of lighting, as for the purposes of cleanliness, 
are composed generally of Jars, filters, drainers, canisters, cruets, 
boxes for this service, lamps, assortment of tools, &c. 

Notwithstanding their brittleness, Jars of varnished clay (earth¬ 
enware) have been generally adopted in the Lighthouses of France 
for the keeping of the Colza oils. The use of large leaden vessels 
ought to be abandoned, causing, as they do, a speedy deteriora¬ 
tion of those oils. 

Ordinarily, the Jars rest on the area of the cellar, and a little 
pump is used to draw off the oil they contain, but it is more con¬ 
venient to place them on a stand, of 50 or GO centimetres in height, 
and to draw off the liquid by means of a cock. 

Keeping and Preservation of the Utensils and Tools. 

The oil filters, which in the Lighthouses and Beacons are in 
daily use, should be kept with the greatest care. This keeping, 
independently of the cleaning of all the pieces of tin, consists es¬ 
sentially in washing with soap every nowand then, the cloth which 
is drawn over the strainer, and in removing the muddy sand in 
order to substitute new sand, which must be previously well 
washed with soft water, and then dried. 

The other utensils do not appear to require any particular men¬ 
tion. 

The collection of tools, which ought to be by so much more com¬ 
plete, as the lighthouse is more important, and more insulated, 
comprises usually a sufficiently great number of pieces in iron or 
steel, which are not in habitual use. 

They require, for that very reason, particular care for their 
preservation, and it is essential to guard them from oxydation, by 
having them constantly rubbed with lard, or other fresh grease. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 23 

SECTION 4. 

SUPPLIES OF OIL, WICKS, CHIMNEYS, LINEN, ETC. 

Supplies of Colza Oil. 

Tne Oil of Colza of the first quality, perfectly clarified, and 
purified, ought to be exclusively employed iu illuminating the 
Lighthouses and Beacons on the coasts of France. (1.) 

Clear oil, of a greenish-yellow colour, having a well defined 
taste and odor of cabbage, without being nauseous, may be pre¬ 
sumed of a good quality for giving light. 

Oil of a reddish tint, exhaling a foetid odor, contains very often 
a certain proportion of fish or whale oil. By the effect of this 
fraudulent mixture, the wicks burn away, and require snuffing 
at the end of some hours. 

The decisive test for the verification of the oil of Colza, is the 
trial of it in an ordinary or mechanical Lamp, which is kept burn¬ 
ing fifteen or sixteen hours without interruption. If, during so 
long a combustion, the flame keeps up to the proper height, and 
the wick require no snuffing, the oil may be pronounced receiv¬ 
able. (2.) 


(1.) Article 3d of the Document exhibiting the charges made by the company con¬ 
tracting for lighting the coasts of the Ocean and of the Mediterranean ; and Article 
2d of the clauses, and conditions relative to the furnishing of oil for lighting the coasts * 
of La Manche, or the English Channel. 

(2.) The areometer furnishes a means of verification which from every appearance 
w’ill soon be generally adopted by the purifiers and retailers of Colza oil. This method 
appears so much the better, as this oil is lighter than any of those which it could be the 
interest of dealers to mix with it, and which adulteration would not appear at first 
view. We exhibit, from Berzelius, the specific gravities of several vegetable and ani¬ 
mal oils. Added thereto is the indication of the corresponding degrees of the centigrade 
alcoometre. 



Specific 

gravities. 

Degrees 
of the al¬ 
coometre. 


Specific 

gravities. 

Degrees 
of the al¬ 
coometre. 


Specific 

gravities. 

Degrees 
of the al¬ 
coometre. 

Suet 

0.90.03 

66 

White mustard 

0.91.42 

60 

Cameline 

0.92.52 

54 3-4 

Rapeseed 

0.91.25 

60 3-5 

Olive 

0.91.76 

58 2-5 

Hempseed 

0.92.75 

53 2-3 

Colza 

0.91.36 

60 1-5 ! 

Whale - 

0.92.31 

58 4 5 

1 

Flaxseed 

0.93.47 

50 

I 1 


• 

Poppy - 

0.92.43 

55 1-4 

Ricenius 

0.96.11 

33 3-4 


✓ 


5 






























34 CODE OF INSTRUCTION ON LIGHTHOUSES. 

fn the Lighthouses supplied by contract, the oils provided are 
never considered as definitely received, so that the Engineers 
have always the power to insist on the withdrawal and the re¬ 
placing of those oils whose bad quality they have tested. 

In the Lighthouses of the first division of the Coast, this power 
expires at the end of a month, dating from the day of the delivery 
of the oil at the store room of the Lighthouse. (Art. 9, of the 
Book of Charges, for 1839.) 

The Colza oils deteriorate after a lapse of time, and the decline 
is hastened by exposure to frequent changes of temperature. 
There is therefore a disadvantage in laying in too large a supply 
of this sort. 

The limit would appear to be fixed at half a year’s consumption. 

Cotton Wicks. 

The Cotton Wicks ought to be of a size exactly fitted to that of 
the burners of the Lamp, and of an even web, neither too thin nor 
too thick. 

They must be kept carefully wrapt up in paper, and in boxes, 
carefully preserved from dust and damp. 

The supply of wicks ought not much exceed the demand for 
one year : that is to say, 19 to 12 metres of each sort to a burner. 

Glass Chimneys. 

The choice of Glass chimneys is of a greater importance for the 
regular developenient and steadiness of the flame of a Lamp. 
They should present as exactly as possible, the dimensions and 
forms recognized as most suitable, particularly in regard to their 
diameter and to the curvature of their bulge. 

With those whose bulge presents a right angle, a white and 
steady flame is commonly obtained, but it is not always possible 
to raise it to the developement required. 

The elongated form of this bulge or elbow is more favorable in 
this regard ; but there generally results from it a flame more agi¬ 
tated, and somewhat less clear. 


To compare these observations more certainly we can bring them to the temperature 
of boiling water by means of the bain-marie , (a vessel lull of water, with one or more 
alembics.) The oleometer is arranged on this principle. The use of this apparatus has 
prevailed for some time past amongst the purifiers of oil in Paris and Lille. 






CODE OF INSTRUCTION ON LIGHTHOUSES. 


35 


The latest experiments tend to award the preference to the 
elongated elbows. 

It is essential that the glass chimneys be well made, and it is to 
be observed, on this subject, that the thinnest, all other things 
being equal, are least liable to be broken by the effect of changes 
of temperature. The number of chimneys in store should not be 
less than sixty for a Lighthouse with a mechanical Lamp, nor less 
than forty for a beacon with an Argand burner. 

Different Supplies. 

Conformably to the 11th article of the new Code of Charges by 
the Contractors for lighting the coasts of France, every Lighthouse 
is to be always provided, for one year at least, with curved scis¬ 
sors, scrapers, kidskin, polishing rouge, sheepskin, watchmakers’ 
oil for the movements of the Mechanical Lamps, (1,) spirits of 
Wine, spirits of Turpentine, Linseed oil, boiled oil, white lead, 
Spanish white, hand brushes, (called Bakers’ brushes,) Watch¬ 
makers’ brushes, Rat-tails (brushes) to clean the burners of Lamps, 
hair brooms, common brooms, and sponges. 

This enumeration may suffice without more ample details. We 
shall merely remark that it comprises the substances necessary for 
the making of putty, which the Keepers should know how to pre¬ 
pare, and use for the ordinary repairs of the Lanterns. 

Linen. 

The Linen annually furnished to the Lighthouses and Beacons, 
is composed of Napkins and Dusters of a prescribed quality. This 
article of supply did not appear in the old contracts. The Con¬ 
tractor was bound only to furnish the quantity of Linen necessary 
for the uses of cleaning; but that sort of agreement was found 
subject to such abuses as caused its discontinuance. 

‘A------- 

(1.) Three sorts of oil are known in commerce, under the name of Watchmakers’ 
oil : namely, NeaVs-foot oil , Sheep’s-foot oil, and pure Olive oil. 

The two*first have an advantage over the third, in not congealing except at a very 
low temperature. 

Neat’s-foot oil is yellowish and void of smell, in a pure state. It appears, moreover, 
that it is more generally adulterated than the Sheep’s-foot oil, which is of a white 
colour. 

As to the Colza oil, it should never be employed to grease the wheelworks, on ac¬ 
count of its property of coagulating quickly when exposed to the air. 




36 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


The Code of Charges, and the calculated detail, which has 
served as a basis for the renewal of the Contract for lighting the 
Ocean Shores, and those of the Mediterranean, regulate, as follows, 
the number of Napkins and Dusters to be furnished annually to 
every Lighthouse, as also for every Beacon of the 4th order, pro¬ 
vided with a Keeper’s Lodge and Store Room : 



Napkins. 

Dusters. 

1st order ------ 

6 

12 

2d order ------ 

5 

10 

3d order ------ 

4 

8 

) with a hydrostatic Lamp 

4th order > 

o 

4 

) with an Argand burner - 

1 

o 

/W 


Every one of these pieces should be marked with the year of 
its delivery, and its regular number, so as to facilitate the counting 
and examinations. 

SECTION 5. 

KEEPING THE BUILDINGS IN ORDER. 

The keeping in order those buildings attached to the Light¬ 
houses and Beacons, has a very direct, and a very marked influ¬ 
ence on the Lighthouse service. This service demands, in fact, 
as a first condition, order and cleanliness. Now, these qualities 
cannot be obtained, if, from the very threshold of the Lighthouse, 
the arrangement of the Lodges, and Store-rooms do not impose on 
the keepers a line of conduct, and course of habits unfortunately 
too rare amongst the working-classes. 

■ 

Furniture for the Keepers' Lodges. 

It is necessary that the Keepers’ Lodges, attached to the Light¬ 
houses and Beacons of any importance, be furnished with the 









CODE OF INSTRUCTION ON LIGHTHOUSES. 


37 


principal articles of indispensable furniture, so that the change of 
a Keeper may not be clogged with the embarrassments of house¬ 
furnishing. It is, moreover, proper that this furniture, without 
being elegant, should be well made, and to a certain degree, in 
Iiarmony with the importance of the Establishment. 

Closets in sufficient number, ought to be established, some for 
the personal use of the Keepers, and the others to be exclusively 
appropriated to the preservation and methodical classification of 
the supplies of Linen, Cotton wicks, Kidskin, Polishing Rouge, 
&c., as also the common utensils, tools, extra-pieces, and various 
matters which it is necessary to keep free from dust and damp. 

Cases should be arranged to receive, and exhibit at all times, 
the lenticular panes and extra glasses, as also the glass chimneys. 

When those various objects, instead of being thus methodically 
arranged, remain shut up in chests, we are daily subject to the 
inconvenience of a long search for whatever may be needed, and 
after all, often find it injured and unserviceable. 

CHAPTER II. 

PERSONNEL. 

The Illumination of the Lighthouses and Beacons is entrusted 
to Keepers. The number of these agents is ordinarily fixed, as 
follows: 

1st order.3 keepers. 

2d ..2 - 

3d ..2 - 

4th...1 - 

If the Lighthouse be out at sea, the number of Keepers is in¬ 
creased to 4 for the first order, and 3 for each of the three others. 

Night - Watches. 

The service of the Lighthouses of the three first orders cannot be 
suitably performed, unless the Light is inspected during the whole 
night, by each keeper while on his regular watch. (1.) 

When there are only two keepers, one takes his watch from 

(1.) This Injunction is not peculiar to the Dioptric Lighthouses illuminated with 
mechanical Lamps. In England, where the greater part of the Lighthouses are still 
lighted by reverberators with the common Argand Lamp, an uninterrupted watch 
during the whole night is rigorously exacted. 















38 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


sunset ’till midnight, and the other, from midnight ’till day-break. 
The next night, they keep three watches, in order that the fatigue 
may be equally shared. s 

In Lighthouses provided with three keepers, the service of each 
night may be equally divided amongst them, or else, one of the 
three can take his entire rest, and perform double-watch the fol¬ 
lowing night. 

Of these two combinations the first would appear to be prefer¬ 
able, as the duty from sunset ’till 10 or 11 at night is not very 
fatiguing, and it is important to abridge the more painful service 
of the remainder of the night. 

Service of the Morning and of the Day. 

From the dawn of day, and immediately after the extinction of 
the light, the keepers should employ themselves in preparing 
every thing for lighting up on the following night, and in pro¬ 
viding things necessary for cleaning, &c., so that the different 
operations prescribed for the morning service , by special instruc¬ 
tions, (and particularly the renewal or trimming of the wicks) 
should be completely finished two hours after sunrise. 

It is very essential to attend to this rule, which is too often 
neglected. 

During the day the iveekly keeper should be constantly on guard 
at the Lighthouse, and all the keepers should repair to their posts, 
at the latest, two hours before sunset. 

Evening Service. 

The Evening Service (for the details of which we refer to the 
special instructions) requires the attendance of two keepers, at 
least, in Lighthouses of the three first orders ; and if a Lighthouse 
of the first order, the three keepers must act in concert on this 
service. 

The lighting up of every Lighthouse with a mechanical Lamp 
should commence a quarter of an hour before sunset, so that the 
light may be in full force at twilight. 

Register. 

Each keeper, during his watch, should take exact note— 

1st. Of the irregularities which the Lamp in use (as also of the 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


39 


Rotary Machine, if it be a revolving Light) may have experienced 
in its progress. 

2d. Of the state of the atmosphere, and the direction of the 
wind. * 

3d. Of the appearances of the Lights in sight. 

These notes are copied into a Register kept for that purpose. 

Inventory . 

Two other Registers should be kept, one for the Inventory of 
furniture, the other for the state and condition of the store Room 
containing the oil and other supplies. 

From this last Register are extracted the monthly reports which 
are addressed to the Engineers or the Contractors, according as 
the Lighthouse is supplied, by superintendence or by contract. 

Rule of Service . 

A special Regulation should determine the duties of the keepers 
relative to the daily and periodical cleaning of the apparatus for 
lighting, as also of the various parts of the building. These agents 
are required, among other injunctions, to oil the bolts, locks and 
latches of the different fastenings, as often as necessary, and to 
keep the frames of the Lantern well puttied. 

Head Keepers. 

In Lighthouses served by several keepers, one of them receives 
a high salary, with the title of head- keeper. He is specially 
responsible for the safe-keeping of the furniture and supplies, as 
well as for the enforcement of the rules of the service; and is, 
besides, charged with the keeping of the Registers, and the cor¬ 
respondence. 

The head-keeper should likewise unite with the other keepers 
in the services of lighting and cleaning ; there being no distinction 
amongst them, or special privilege, in this respect. 

Choice and Nomination of Keepers. 

In order for admission to the duties of a Keeper of a Lighthouse 
or Beacon, the applicant must be of sound health, know how to 


40 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


read and write, have complied with the conscription Laws, and 
not be over 45 years of age. 

The Keepers of the Lighthouses and IJeacons on the Ocean and 
the Mediterranean are chosen by the Commission of Lighthouses, 
or its agents, under the sanction of the chief Engineer. 

In the new organization applied to the service of lighting the 
coasts of the channel, these agents are named by the Prefect, on 
the suggestion of the Engineers. 

Salary of Keepers. 

Under both forms, the salary fixed by the administration should 
be paid without any deduction to each keeper, except those for¬ 
feits kept back, for violation of the rules of the service. 

Instruction. 

The instruction of new and inexperienced keepers demands 
special attention, and is ordinarily entrusted to one of the conduc¬ 
tors attached to the central service of the Lighthouses. 

Leave . 

No leave of absence should be granted to the Keeper of a Light¬ 
house, except for weighty reasons, and is available only under 
the signature of the Engineer of that department. 

It should also be understood, that if the number of Keepers is 
less than three, none of them can absent himself without provid¬ 
ing a substitute. 

Families of the Keepers. 

Those Lighthouses isolated out at sea should be inhabited only 
by the keepers; but the families of those agents may be admitted 
in the Lighthouses, not isolated, where there are accommodations 
sufficiently roomy, and having no immediate communication with 
the tower of the Lighthouse. 

This last proviso applies only to Lighthouses properly so called, 
and not to those secondary Beacons kept by one keeper only. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


41 


THIRD SECTION. . 

DIRECTION AND INSPECTION OF THE SERVICE OF LIGHTHOUSES 

AND BEACONS. 

The Explanations given in the two preceding sections, both on 
the principal systems of apparatus applied to lighting the coasts of 
France, and on the organization of the service of Lighthouses 
and Beacons, embrace every thing essential to be known for the 
management and superintendence of these Establishments. This 
third and last section shall be, therefore, in many respects, (as we 
have said in the Introduction,) merely a summary and corollary of 
the other two. It will, however, exhibit some new develope- 
ments on those points upon which it has appeared necessary to 
dwell. 

Agreeably to the order observed in the first section, we shall 
first discuss the subject of the Lenticular Lighthouses and Bea¬ 
cons, reserving for a last chapter those observations specially rela¬ 
tive to the service of Catoptric apparatus. 

CHAPTER I. 

LENTICULAR LIGHTS OF THE THREE FIRST ORDERS. 

it happens, pretty generally, that in visiting a Lighthouse, the 
establishment is examined, as a whole, before entering into the 
details relative to the Lighting Apparatus, as also the utensils and 
supplies necessary for its service. But the means for lighting, 
and the employment of those means, being the capital object for 
consideration, ought to have the priority here. 

SECTION 1. 

LIGHTING APPARATUS AND LANTERNS. 

-In the course of inspection, the lenticular apparatus should be, 
before all, examined on the following points : 

1st. The position of the burner of the Lamp in use. 

2d. The condition of this Lamp. 

3d. The condition of the Optic pieces. 

4th. The condition of the Rotary Mechanism, if it be a revolv¬ 
ing apparatus. 

6 


42 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


In order to ascertain if the Lamp of the apparatus is well cen¬ 
tered, you must stretch the two diametral threads of the lenticular 
drum and fit upon the burner, the wooden gauge prepared for 
this purpose. You next verify by means of a small level with 
air-bubbles, the horizontality of the crown of the burner. 

After this double verification you examine if the pieces of the 
Mechanism of the Lamp are free from dust, if the pivots are not 
clogged with old oil, and finally, if this mechanism performs with 
regularity under the action of a weight, which exceeds not the 
ordinary limit. 

If it be a clockwork-movement, particular attention is to be 
paid to the flyer, the wings of which, in its proper situation, are 
inclined 45 degrees. 

If the pistons of the Pumps are attached to a horizontal system of 
small cogged wheels, the relative positions of those wheels should 
be verified. They ought to interlock in such sort, that, when two 
of the Pistons have reached the opposite limits of the whole 
course, this course becomes regularly divided by the respective 
positions of the other pistons. 

In the case of unequal division, the ascension of the oil would 
be irregular, and it would be necessary to remedy this inconve¬ 
nience by making the small wheels in question resume the rela¬ 
tive positions marked on them. 

In all Lamps fed by pumps with pouches, you should examine 
if the little valves be either too open or too large, and if they 
do not admit the air to penetrate in some point. 

In such cases the remedy is very simple, since a renewal of the 
leather pouches is all that is necessary, an operation familiar to 
the keepers of Lenticular Lights. 

This renewal will be facilitated, in future, by the use of brass 
moulds, with the aid of which they can, without groping their 
way, cut and fit the valves of the pumps. 

In the inspection of Lamps with an escapement with pegs (sys¬ 
tem Henry Lepaute) the play of the escapement should claim par¬ 
ticular attention. If some inequality should be manifested by 
shocks or stops, the cause must be sought for, which may be one 
of the following: 

1st. The bad fit, or the deterioration of the valves. 

2d. The obstruction of the regulating hole. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


43 


3d. Its enlargement by awkwardly executed cleansings. 

4th. Some loosening of the screws attached to the escapement 
burners, or of the screws serving as axis to the rollers of the 
horizontal wheel. 

We have just pointed out the remedy for the first case. 

The obstruction of the regulating hole yields ordinarily to a 
moderate effort exercised pressingly with the aid of the Key or 
crank by which the clockwork is wound up. 

The enlargement of this orifice requires the renewal of the 
diaphragm in which it is pierced. To remove this chance of 
disturbance, the diaphragm is now made of steel. 

In the inspection of the mechanism of the Lamps with crooked- 
levers (system J. Wagner, nephew) we must first examine: 

If the relative position of the crooked-Levers is such, that there 
may be neither shocks, nor lost time, 

And, if the stems of the two pistons play freely in their leather 
boxes. 

We must next observe, in regard to Lamps of every sort: 

If all the parts of the burner are well cleaned, and especially 
if the spaces reserved for the currents of air are not obstructed 
by any filth which would cause the wicks to smoke and clot. 

If those wicks are regularly trimmed. 

If the moveable glass-holder which bears the glass chimney 
revolves freely, so that it may be easily raised or lowered, in 
order to increase or diminish, at will, the developement of the 
flame. 

Finally, if the key of the Sheet-iron damper fit easily in all the 
inclinations. 

To complete this first examination, it will be well, (if it take 
place by day) to set the Lamp, not lighted, agoing, and to collect 
in a vessel the product of the pumps, in order to measure or weigh 
it. This product, in its regular state, should equal, as we have 
seen above, four times the hourly consumption, that is: 


For the 1st order.3 kil. or 3 litres 30* 

For the 2d ..2 or 2 - 20 

For the 3d .. 0,760 or 0 - 84 


There are, in most of the Lighthouses lit by mechanical Lamps, 
tin measures intended for these verifications. 


* Litre, an English qnart and nearly. 











44 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


The Light-keepers are generally disposed to carry to the maxi¬ 
mum the product of the oil-pumps of the mechanical Lamps, and, 
in this respect, the means of verification differ according as vve 
have to consider Lamps with clockwork-movement having a fly 
for regulator,—or, Lamps on the new system, in which the oil 
flows through a small orifice. 

To accelerate the play of the mechanism with a flyer, the 
keepers often dispose the wings of this Regulator, so as to reduce 
to its minimum the resistance of the air, and they exult at the 
same time, because they are enabled to lighten the motive weight. 

In this state of things, the rim of the burner, cooled by the ex¬ 
cessive current, can no longer distil the quantity of oil necessary 
for the regular developement of the flames, unless the wicks are 
raised above the limit of 7 millimetres. Rut this palliative cannot 
be admitted, for the effect would be, to raise the luminous centre 
above the focal plane of the lenticular system, and consequently, 
give the rays a downward direction, and reduce the reach of the 
Light. 

In such case, we must, as much as possible, bring back the play 
of the Lamp to its regular state, by rectifying the wings of the 
flyer ; increasing, however, the motive weight to the utmost limits 
allowed by the mechanism. 

If it be an escapement-Lamp having a small orifice whose ex¬ 
penditure of oil can be regulated only by the load, more or less 
heavy, of the motive-weight, we must examine if this weight is 
not excessive, or if, on the other hand, its insufficiency does not 
cause occasional stoppages, and too glaring oscillations of the 
flame. 

If we cannot possibly be present at the night-service, we can 
direct the Lamp of the apparatus to be lit by day, in order to be 
sure that it performs regularly, and that the keepers know how to 
raise and keep up the flame to the required height. (1.) 

This result, so essential, and which sums up, in some degree, 
all the Lighting Service, is, unfortunately, very difficult to obtain 

(!•) For this simple repetition, vve proceed generally in a way, somewhat more 
rapid than indicated in the 23d, 24th and 25th articles of the Code of Instructions for 
the use of Keepers; that is, instead of employing one hour to raise the flame to its full 
developement, it is carried to its full height in half an hour. The wicks are, in this 
way, clotted, and require to be afterwards trimmed lor the evening Light. 






CODE OF INSTRUCTION ON LIGHTHOUSES, 


45 


from those agents. To succeed in this, it is necessary to wrestle 
with constancy against their too general proneness to keep the 
flames low ; and to know how to show, when needed, an example 
of just severity. 

They allege, usually, in order to palliate their infractions of 
the 25th article of the Code of Instructions, for 1835, the danger 
of making the Lamps smoke, and of breaking the glass chimneys. 
But the true explanation is oftener found in that laziness which 
endeavours to escape from the trouble of the careful superinten¬ 
dence, required in order to keep up the flame at its full develope- 
ment. 

In the inspection of the lenticular panes and of the mirrors com¬ 
posing the optic part of the apparatus, we should carefully ascer¬ 
tain if the processes of cleaning are not irregularly and awkwardly 
performed. This is known by the little streaks which do not fail 
to appear on the surface of the glasses, when they are wiped with¬ 
out first having been dusted, or when badly prepared rouge is used 
in cleaning them. 

When there is reason to suspect that some mirror has been dis¬ 
placed, its position is verified by proceeding as follows : 

If it be a mirror of the upper Zones at the lenticular drum, 
the burner of the Lamp in use is taken off, and in its place is put 
a vertical stem having its summit at the focus of the apparatus. 
That being done, the eye is placed at the focal point, in order to 
ascertain if the horizon of the sea is depicted on the middle of the 
glass which is to be verified. In the contrary case, the lowering 
screws are to be put in play until this result be obtained. 

If it be a mirror lower than the lenses, we take the point of 
sight on a level with the upper edge of the burner, on the part 
nearest to this mirror, and at 10,8, or 6 millimetres above the said 
burner, according as we have to deal with an apparatus of the first, 
second, or third order. 

It happens that the tin plating of the mirrors of the lower Zones 
decays after some time, by the action of the solar rays, and some¬ 
times also by damp. 

The first cause is obviated by taking care to keep during the 
day, the apparatus covered vrith its glass holder, and the access of 
damp is prevented by strict attention to the puttying of the frames 
of the mirrors. It is seldom, indeed, that the punctures of the 


46 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


mirrors are of a nature to reduce, very much, the quantity of light 
reflected. 

Examination of the Rotary Mechanism of Apparatus with re¬ 
volving Lights. 

After this verification of the state of the Lamp, and of the optic 
part of the apparatus, we shall have to examine the mechanism of 
rotation, assuming it to be a revolving Light. For this purpose, it 
must be put in motion, and the duration of a revolution verified. 
If the motion is found too rapid or too slow, it must be regulated, 
as above indicated, according to the Code of Instruction for 1835, 
(art. 63.) 

If the weight necessary for the regular motion exceed, in a re¬ 
markable degree, the ordinary limit, the causes of the excess of 
resistance must be ascertained. For this object, we shall first 
verify, with a level (air bubble) of 15 to 20 centimetres, the hori- 
zontality of the plane upon which the circular Car of the moveable 
apparatus revolves. We can then unlock the upper wheel of the 
machine, in order to ascertain if the causes of stoppage do not ori¬ 
ginate in this machine itself, of which we shall be able to judge 
by the weight necessary to make it perform its functions. 

If the circular platform is warped, we can underprop the sup¬ 
porting column of the apparatus, in the manner above described. 

If the irregularities of the motion are in the machine itself, 
it can be taken down, cleaned, and put up again by the keepers, 
or, it can be examined, and repaired when necessary, by a regu¬ 
lar clockmaker. 

After this first examination of the apparatus, the keepers should 
be required to produce the supernumerary Articles and Utensils, 
which ought to be found collected in the chamber of the Lantern, 
and locked up in a little closet, or in the nest of drawers of the 
table in regular use, if it happen to be a Lighthouse of the first 
order. 

Amongst those Articles we shall particularly note : 

1st. A Lighting-Lantern, with a small hand Lamp, called a 
Lucerne. 

2d. Four spare glass-chimneys. 

3d. One spare burner perfectly clean, and furnished with dry 
wicks. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


47 


4th. One tin box, with compartments, called the service-basket , 
a double assortment of new wicks, curved scissors, two scrapers, 
the forms serving to put on the wicks, two bottle brushes, called 
rat-tails, &c. 

5th. A tin box containing a piece of kid-skin, of 30 or 40 centi¬ 
metres square. 

6th. An oblong box furnished inside with a thick woollen stuff 
on which to cool gradually the glass chimneys withdrawn from 
the apparatus. 

7th. A little stick 40 centimetres in length, furnished with a 
plug of old Linen to clean the inside of the glass chimneys. 

8th. Some Napkins, Dusters, and Rags, and a hand-brush. 

Extra pieces of the Lighting Apparatus . 

Next, pass in review the extra pieces belonging to the Lighting 
Apparatus and its mechanism, namely : 

1st. Two Mechanical Lamps , one of which is kept in a closet, 
within reach of the apparatus, in order to replace when needed 
the Lamp in actual use. 

After having examined all the exterior pieces of these two 
Lamps, so as to be assured that they are well cleaned, the condition 
of the Valves can be ascertained, by taking down the body of 
Pumps. 

2d. Four spare burners , independent of that kept in the cham¬ 
ber of the Lantern. 

If they are not new, they ought to have been perfectly well 
rinsed in ley. It is also essential that they be kept safe from dust 
and damp. 

3d. Two Dampers of Sheet Iron. 

4th. A flying pendulum to replace when needed that of the 
Rotary machine, (if it be a revolving Light.) 

The steel portions of this important piece should be preserved 
from rust by the application of a slight coating of lard or suet. 

5th. Three small Jack-screws to raise when needed the moveable 
iron-work of the revolving apparatus. 

The preservation of these Jack-screws requires the same care 
as that of the spare Flyer. 

6th. The extra Lenticular panes of glass. 

These should be placed upright in a chest with doors, and if 


48 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


many are put up in one case, the} T should be carefully separated 
by bunches of tow. 

7th. The extra Mirrors. 

They ought to be kept in a double envelope of silk paper, and 
of coarser paper, and placed upright in packages well tied up, in 
a closet free from damp. 

Examination of the Lantern. 

The examination of the Lantern will turn particularly on the 
care bestowed on the painting, and puttying, as also on the state 
of the pieces of the Cupola, and of the glazing in general. 

SECTION 2. 

Supplies , Utensils , and Implements. 

To the inspection of the Lighting-apparatus, and of all those 
pieces dependent on it, succeeds, in the order of importance for 
the service, the review of the supplies, as also of the various out¬ 
fits, implements, and utensils placed at the disposal of the Keep¬ 
ers, as well for the Lighting service, as for cleaning and preserv¬ 
ing, namely : 

1st. The Oils. 

These demand special attention under the threefold relation of 
quality, quantity, and arrangements made for their safe-keeping. 

We have seen above by what tokens the quality of Colza oil is 
ascertained, and how it is tested. 

2d. The Cotton Wicks. 

These ought to be carefully wrapped up in paper, and shut up 
in a closet free from damp. 

3d. The Glass Chimneys. 

These ought to be ranged in view, in a chest, and in quantity 
sufficient to serve for two years. 

4th. Kid-skin and English Rouge. 

These should be kept locked up, and safe from dust and damp. 

5th. Extra Cordage for the mechanical Lamps, and for the Ro¬ 
tary machine, if it be a revolving Light. 

6th. Watchmakers’’ Oil for the wheelwork of the Machinery. 

7th. Filters, drainers, hand-pumps, cruets, and other utensils 
serving to draw off the oils. 


49 


CODE OF INSTRUCTION ON LIGHTHOUSES. 

8th. Tools , such as, pincers, hammers, English keys, hand- 
vices, nippers, cutiers, files, &c. 

These should be arranged methodically and suspended at the 
bottom of a screen or sideboard. The pieces of Iron, or of polished 
Steel should be preserved from rust by a thin coating of fresh 
grease. 

9th. The Napkins and Dusters destined for cleaning the Appa¬ 
ratus and Utensils. 

These pieces of Linen should bear the date of the year of their 

•> 

delivery, and also their own regular number, 

10th. The Brooms , Brushes , and Sponges. 

Hth. The Spirits of Wine , Spirits of Turpentine , as well as 
the different substances serving to manufacture glaziers’ putty, 

12th. The extra Glasses. 

These should be in sufficient quantity to glaze completely two 
sides of the Lantern. 

loth. The supply of Combustible matter. 

14th. Finally, Sea Stores , in those Lighthouses where this kind 
of provisions is indispensable for the keepers, 

SECTION 3. 

LODGING AND FURNITURE. 

% 

The inspection of the Lodgings and Furniture is far from being 
without interest for the Lighthouse Service, for, if order and neat¬ 
ness do not prevail in the dwelling of the keepers, disorder and 
uncleanliness will extend infallibly to the Store Rooms and the 
chamber of the Lantern. 

This part of the inspection having nothing which is not common 
to all those of the same kind, calls for no particular remark, un¬ 
less it be of the obligation imposed on the keepers, of oiling, as 
often as it may be necessary, the hinges, bolts, fastenings and iron¬ 
work of the doors, &c. 

The Inspectors should also see that the furniture is well kept. 
It is one of the charges of the Lighthouse contract for the coasts 
of the Ocean and the Mediterranean, and the administration is 
bound to provide for it in the blended system of contract and 
superintendence applied to the service of the Channel Light¬ 
houses. 


50 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


As to the inspection of the buildings, under the relation of 
greater and less repairs, it suffices to mention it here as a note, in 
calling attention however to the keeping of the roofs in good re¬ 
pair, exposed as they are particularly to havoc at certain points 
from every wind that blows. 

SECTION 4. 

/ 

GENERAL CONDITION, REGISTER OF THE WATCH (OR LOG-BOOK.) 

After the inspection of the Materiel, it is well to examine the 
Register and Remarks, the keeping of which Book is entrusted 
specially to the head keeper. 

1st. The Invenlory of the Furniture of the Lighthouse. 

2d. The Journal of Articles brought into the Store Room, and 
of articles taken out. 

3d. The Monthly Statements of the condition of the supplies, 
if it be a Lighthouse in which the Keepers, as Agents of the ad¬ 
ministration have in charge the use of the furniture intended for 
the Lighting service. 

4th. The Register of the Watch, or Log-Book, in which should 
be set down, for every night and for every Watch, the observa¬ 
tions made upon any remarkable circumstance occurring about 
the Lighthouse, as well as upon the state of the Atmosphere, the 
appearances of the Lighthouses in sight, &c. 

In the same Register may be noted all events of a nature inte¬ 
resting to the service, and particularly the visits of the agents of 
the administration, or other functionaries. 

C RAPT Eli II. 

LENTICULAR BEACONS OF THE FOURTH ORDER. 

The Indications relative to the inspection of the lenticular Light¬ 
houses of the three first orders, apply in many respects, to the 
plain Catadioptric Beacons. We can therefore confine ourselves, 
in this second Chapter, to those Observations applying peculiarly 
to this kind of Beacons. 

In the examination of their Lamps, there are two sorts to be 
considered: 


51 


CODE OF INSTRUCTION ON LIGHTHOUSES. 

The ordinary Lamps, with a constant level , and the Hydrostatic 
Lamps of Thilorier. 

Although, trie mode of adjusting Lamps with a constant level 
does not allow of the ordinary means to rectify at need the posi¬ 
tion of the burner, it is well, however, to ascer tain whether it is 
exactly in the centre. 

In order to this, it is required that its middle correspond ex¬ 
actly with the axis of the apparat us, and that the upper part of this 
same burner be placed at a level of 20 or 22 millimetres in a 
line with the horizontal plane passing through the middle of the 
principal ring of the dioptric Drum. 

This first verification being made, we examine if the Lamp is 
well cleaned in all its parts, particularly in the central tube of 
the burner, and if the moveable glass-holder upon which the 
chimney rests can be raised and lowered easily. 

We can next take out the wick to see whether the level of the 
oil corresponds with the required height, that is to say, at about 
2 millimetres opposite the edge of the burner. 

As we have remarked in the first section, it happens too often 
that some rent in the rim of the burner occasions an overflow or 
waste of the oil. In such case, the necessary steps should be 
taken for the prompt repair, or the substitution of another for the 
faulty piece. 

In the newly constructed Lamps, the burner is adjusted by 
means of a screw-level, so that the substitution of a spare burner 
is very easily effected, without the aid of a tinman. But in the 
old Lamps, in order to effect such change, the burner must be 
unsoldered, to take it off, and another soldered on, in the exact 
position which the old one occupied. Now, it is to be remarked, 
that this adjustment, simple as it may appear, is almost always 
badly executed by the Lamplighters of the departments. 

It is very essential not to quit the Beacon, under inspection, 
before we are very sure that the keeper knows how to give the 
flame its full developement, and to keep it up to that point, with¬ 
out glare or smoke. 

If, therefore, the visit take place in the day time, it will be re¬ 
quisite to cause the Lamp of the apparatus to be lighted up. 

The wick and the chimney being regulated to a suitable height, 
we ought to obtain after half an hour, or three-quarters of an hour’s 


52 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


burning, a (lame of 35 to 40 millimetres in height, if the burner 
is of small bore, and of 40 to 45 millimetres if it is of large model. 

Caiadioptric Beacons lighted hy a Hydrostatic Lamp . 

The centrage of the burner of a hydrostatic Lamp, applied to 
the lighting of a Catadioptric Beacon, is so much the more neces¬ 
sary to be verified, as this Lamp is simply placed on a platform, 
the elevation of which can be varied at will. 

For this verification, the Lamp in service is put in its place, 
after which it is to be ascertained that the centre of the burner 
corresponds with the axis of the apparatus, and that the top of the 
rim is 24 to 25 millimetres in fore-front of the focal plane. 

The same verification is to be applied to the two extra Lamps. 

If some difference in height should be observed between the 
three Lamps, it would be requisite after having fixed the stays of 
the moveable platform to the point suitable for the highest lamp, 
to cause tin wedges to be soldered under the feet of the lower 
Lamps. 

The regular tube claims especial examination. It is first ascer¬ 
tained, by means of a brass wire, that no obstruction exists in the 
tube, after which it is put in motion vertically in order to ascer¬ 
tain whether it be tightly closed by its leather box, and whether 
the level of the oil, at the rim of the burner, instantly follows the 

little variation communicated bv the elevation of the tube. 

%> 

In order to judge better of these effects the wick should be pre¬ 
viously removed. \ 

If this instantaneous correspondence did not take place, although 
the canal of the regulating tube offered a free passage to the air, 
we must thence conclude that there exists some obstruction in the 
ascending or descending tube. In such case, the Lamp should be 
completely emptied, and then rinsed out with boiling ley. 

In order that a Thilorier-Lamp should perform regularly, it is 
requisite that the liquid sulphate of Zinc which fills the upper 
reservoir, should have a specific gravity equal to once and a half 
that of the oil. It is therefore essential to be assured that this 
condition is fulfilled, as it has been explained in the first section. 

We shall, moreover, remark, that the flame of this sort of Lamp 
should mount, whemin full operation, up to 45 or 50 millimetres. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


53 


Neatness. 

The clean-keepingof the Catadioptric Beacons requires so much 
the more care, as, being generally but little elevated above the 
shore which they illuminate, they are constantly exposed to the 
sandy dust which the winds raise, and insinuate into the closest 
chambers of the Lanterns. It should therefore be urgently en¬ 
joined on the Keepers, to dust the apparatus in question,and never 
to omit dusting first, whenever they clean the glasses, so as to 
avoid injuring their polish. 

Review of the Extra Pieces , 8{c. 

In order to proceed methodically in the review of the extra 
pieces, utensils and tools dependent on each Beacon, the inven¬ 
tory of those objects should be consulted. 

In this review special attention should be paid to the state of 
the spare lamps and burners. 

If a Beacon with a hydrostatic Lamp is to be inspected, it must 
not be forgotten that the stoppers of the funnel pipes, as well as 
the plain stoppers of the burners are to be produced by the keep¬ 
ers, and also the areometer serving to regulate the specific gra¬ 
vity cf the sulphate of liquid zinc. We must, likewise, be very 
sure, that there is a sufficient quantity of this salt in store, whether 
of a liquid form, or in cakes. 

CHAPTER III. 

REVERBERATORY LIGHTS AND BEACONS. 

If we compare the indications presented in the first section re¬ 
lative to the composition of Catoptric apparatus, with what has 
just been said upon the inspection of Lenticular Lights, and upon 
the Lamps with a constant level of the apparatus of the 4th order, 
we shall easily trace out the line of conduct to be followed, and 
the principal observations to be collected, in the inspection of 
Lighthouses and Beacons on the old system. 

It not being in the power of the Keepers to regulate the cen¬ 
tra ge of the burners in the parabolic Reflectors, that matter is not 
included in the injunctions imposed on them, and the verification 
may be dispensed with, unless there be reason to suppose that 


51 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


some error has been committed in this part of the construction of 
the apparatus. 

The case is different with regard to the position of these reflec¬ 
tors on their iron frame-work. It happens pretty frequently that 
from the effects of rust, or the bad flt of the fastenings, they in¬ 
cline towards the sea, or rise towards the sky, in either of which 
cases, the greater part of the luminous body of rays, is lost to the 
Navigator. 

The regular position answers to the vertically of the plane of 
the opening of the paraboloid, if the Light is not very elevated. 

If the focus rises above the level of the sea by more than 75 or 
SO metres, the axis of the reflector may be slightly inclined so 
that its lengthening may coincide with the dip of the horizon. 

Moreover, whatever may be the position assigned to the reflec¬ 
tor, it is necessary that the rim of the burner should be level, and 
if any rectification were to be made in this respect, it would re¬ 
quire the assistance of a skilful Lamp-maker. 

In the inspection of sidereal Reflectors with two parabolic plates, 
care must be taken to examine whether the dripping-pan placed 
under the lower plate, is not so set, that when it becomes filled 
with oil, it may obstruct the current of air required for the burner 
of the Lamp, and so cause it to go out. In such case it would be 
necessary immediately to make some large sloping cuts in the 
edges of the dripper. 

The mode of cleaning Reflectors is one of those points most es¬ 
sential to be looked into on visiting a Catoptric Lighthouse or Bea¬ 
con. For the quantity of Light reflected can vary precisely as 
the polish of the metallic Mirror is well or ill kept up. It should 
therefore be insisted on that the English Rouge used for this pur¬ 
pose, be carefully purified according to the method pointed out in 
the Code of Instructions, for 1835. (Art. 71.) 

We will remark, while on this subject, that the resilvering of 
the Reflectors which forms part of the obligations of the contract 
for illuminating the shores of the Ocean and of the Mediterranean, 
refers only to those reflectors not plated, and simply silvered, as 
they were manufactured formerly. 

If it be a sidereal Reflector suspended from a cross-beam, the 
inspection should be extended to the mechanism by means of which 
the Lantern is raised and lowered. 


CODE OF INSTRUCTION ON LIGHTHOUSES. 


In the review of the extra pieces and utensils belonging to the 
Beacons of this last sort, we will have particularly to verify the 
number of wick-holders, and also the glass-holders fit for service. 

More ample explanations in regard to Catoptric Lights and 
Beacons, would appear to be so much the less necessary, as their 
service embraces many details common to the lighting of ciiies, 
as well as to domestic Lamps. 

Presented [submitted] for the approbation of the under Secre¬ 
tary of State, for Public Works. 

Chief Engineer and Director, 

Secretary of the Lighthouse Bureau, 

(Signed) L. FRESNEL. 

Seen and approved—Paris, 17 Nov., 1841. 

The under Secretary of State for the Public Works. 

(Signed) Legra^d. 







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